Field of the Invention
The present invention relates to a moving body recognition system that recognizes a moving body such as a vehicle or pedestrian.
Description of the Related Art
With automatic driving of a vehicle or preventive safety technology as an object, acquisition of information for avoiding collision with a vehicle or pedestrian is carried out utilizing acquisition of visual information using a camera or the like, detection of a moving body using a sensor such as infrared radar or millimeter-wave radar, or a communication network (hereafter referred to as infrastructure communication), such as a device that communicates between vehicles (hereafter referred to as inter-vehicle) or a communication device installed on a roadside or the like (a roadside unit) and a vehicle communication device (hereafter referred to as road-to-vehicle).
For example, detection of a moving body using millimeter-wave radar is such that distinguishing of the position and category of a moving body is carried out by the millimeter-wave radar being directed in a predetermined direction and transmitted, and reflected waves from a moving body existing in that direction being detected, measured, and analyzed. The position of the moving body is detected by the delay time between transmitted millimeter waves and received millimeter waves, or the like, while the category of the moving body is distinguished by distinguishing the strength of electric waves reflected from the moving body. When attenuation of the reflected electric waves is small in comparison with the transmitted electric waves, the moving body is seen to be a strongly reflecting moving body and thus determined to be a vehicle, while when the reflected electric waves are weak electric waves, the moving body is determined to be a human body.
Also, infrastructure communication such as inter-vehicle or road-to-vehicle is such that acquisition of information on the position, velocity, and the like, of another vehicle, a pedestrian, or the like, is carried out in accordance with electric waves output from a roadside unit, another vehicle, or a portable terminal possessed by a pedestrian or the like, using dedicated short range communications (DSRC) or the like.
Furthermore, as positional information of a communication device mounted in a vehicle is information obtained from a global positioning system (GPS), the information includes a slight error, and the error is of a size that cannot be ignored with respect to the size of the vehicle, because of which there is technology whereby the existence of a vehicle with which there is a danger of collision is more accurately recognized by positional information of another vehicle being recognized by the communication device mounted in the vehicle, and the positional information being corrected by information obtained by radar, as disclosed in Patent Document 1.
Patent Document 1: Japanese Patent No. 4,569,652
As disclosed in Patent Document 1, being able to more accurately recognize the existence of a vehicle with which there is a danger of collision by an error included in positional information of a vehicle acquired by infrastructure communication, with positional information of a peripheral vehicle traveling in the same direction on a road with multiple lanes as a target, being corrected by information obtained by radar, and a change in the position of the peripheral vehicle with respect to the vehicle itself being estimated, is important in accurately ascertaining the positional relationship of the peripheral vehicle to the vehicle itself.
However, information on a peripheral vehicle alone is not sufficient with respect to a sudden appearance of a vehicle, pedestrian, or the like, from a region forming a radar blind spot at a multiple of intersections and the like existing in a road, and further improvement is needed as a way of avoiding collision.